Touten

Great stuff.
Hi all,
Question 1: If I get this right the LED1 is just for show when relay in on.
Question 2: What does R1 do AND is it necessary.
Question 3: The relay used here wether it’s 80mA (as said in the tutorial)or 200mA (as said in one of the posts) uses too much current for the arduino Uno: max 40 mA (or 20 mA sustained I forget where I read that), and therefor needs an external power source like a 12V AC adapter.
Question 4: If I use an arduino board to send the signal to the transistor thru R2 does the ground of the arduino board need to connect to the ground of the external power source running the relay coil need to be connected together AND if so why.
Question 5: What does “load traces” mean in the post of jan 19 2011 is that what you call the lines on a printed circuit board or is it the mesure of it capacity to handle current.
Thank you very much.

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